1. Field of the Invention
The present invention relates to a apparatus which cuts a piece of long material, such as, for example, a rod, and, in particular, to a cutting apparatus such as a horizontal bandsaw machine.
2. Description of the Related Art
A cutting apparatus such as a horizontal bandsaw machine for cutting a workpiece provided with a cutting head, which is freely movable in the vertical direction, equipped with a cutting tool such as a bandsaw and the like, is commonly known. In addition, a main vise device is provided, having a fixed vise jaw and a movable vise jaw for grasping the workpiece in an immovable state when a workpiece is cut with this cutting tool. In addition, the cutting apparatus has a feed material vise device which, similar to the main vise device, has a fixed vise jaw and a movable vise jaw, and grasps the workpiece between these vise jaws. The feed material vise device is capable of freely reciprocating movement in the longitudinal (front-to-rear) direction to feed the material. The main vise device is positioned in a rear location slightly separated from the position where the workpiece is cut by the cutting tool. The feeding vise device is generally positioned at the rear of the main vise device.
Generally, in the above configuration, when the fixed vise jaw and the movable vise jaw in the main vise device grasp and hold a workpiece, the cutting head moves down from its raised position to cut the workpiece with a cutting tool of the cutting head. When the cutting head reaches the lower most position to complete the cutting, the cutting head is automatically moved back to the original raised position. Then, the workpiece is released from holding by the fixed vise jaw and the movable vise jaw in the main vise device, and the material feed vise device grasping the workpiece in a predetermined retreat position advances and approaches as close as possible to the main vise device, and feeds the workpiece in a fixed dimension unit. When the material feed vise device reaches the advance end position and is at its closest to the main vise device, the workpiece is once again grasped and secured by the fixed and movable vise jaws on the main vise device. In this way, after the workpiece has once again been grasped and secured by the main vise device, the grasp of the workpiece by the fixed and movable vise jaws of the material feed vise device is released, and the material feed vise device once more retreats to a set position. In this retreat position, the material feed vise device once more grasps the workpiece, and remains in the state in which it is capable of performing the next feed action. As outlined above, the workpiece is now once again securely grasped by the main vise device, and, once the material feed vise device has returned to the previously set retreat position, the cutting head once again descends, and once again cuts the workpiece with the cutting tool.
By repetition of the above type of action, the cutting of a long workpiece into fixed dimension units is progressively carried out. After the workpiece is repeatedly cut in this manner, the material feed vise device in the retreat position grasps the rear end of the workpiece, and after the final material feed action and cutting of the workpiece has been carried out, the dimension from the cutting position to the rear end of the workpiece is of a length which can no longer be fed, so a remnant remains.
Accordingly, if the dimension of the remnant material is R and the fixed dimension of the cut length is T, when the final material feed action has been carried out by the material feed vise device and the length L of the workpiece has the relationship L&gt;T+R, it is still possible to feed the material at a fixed dimension. However, when L&lt;T+R, it is not possible to feed forward by the fixed dimension cut length T from the cutting position of the cutting apparatus, and a remnant material of dimension L produced is longer than the fixed dimension cut length T. This results in a large amount of waste.
In addition, as outlined above, the material feed vise device moves reciprocatingly in the longitudinal direction to feed the workpiece, the fixed vise jaw on the material feed vise device contacts the workpiece, resulting in a large frictional resistance. In addition, damage to the workpiece can easily result
Specifically, the fixed vise jaw on the material feed vise device is secured in a fixed position, and when the materials feed vise device retreats from the advance position, the fixed vise jaw contacts the side surface of the workpiece. Accordingly, a material feed vise device provided with a fixed vise jaw which can be moved slightly in the direction away from the workpiece has been developed to avoid this contact between the fixed vise jaw and the workpiece.
However, a hydraulic cylinder for slightly separating the fixed vise jaw from the workpiece is conventionally provided on the outside of the fixed vise jaw. Accordingly, the fixed vise jaw and this hydraulic cylinder are positioned in series and the overall structure is comparatively large, giving rise to the problem that the piping for the hydraulic cylinder is externally exposed, and in addition to worsening the outward appearance, damage to the unit from external sources readily occurs.
Further, when the workpiece is being grasped by the fixed and movable vise jaws of the material feed vise device, a large stroke is provided for the hydraulic cylinder handling the reciprocating movement of the movable vise jaw to allow it to conform to a variety of workieces in larger sizes. In this type of hydraulic cylinder, with the configuration where the movable vise jaw is mounted on the body of the cylinder, the reciprocating configuration is such that the body of the cylinder is guided by a guide section which is formed on the material feed vise device. Accordingly, in the case where it is desired to improve the rigidity of the overall configuration of the movable vise jaw side, the cylinder body must be made wide and large, and changes must also be made to the piston and piston rods.
In addition, in conventional devices, a configuration which positions the material feed vise device toward the retreat position comprises a positioning stopper which freely adjusts the position in the longitudinal direction. The configuration is such that the material feed vise device touches against the positioning stopper. The mechanism for positioning the positioning stopper in the longitudinal direction comprises a rotating threaded rod, extending in the longitudinal direction, which causes the positioning stopper to move in the longitudinal direction. In addition, the positioning stopper is positioned n the longitudinal direction by reading the number of revolutions of a counter which is linked to a threaded rod through a plurality of gears.
Accordingly, in the conventional device, backlash exists between the threaded rod and the positioning stopper, and between the plurality of gears which link the threaded rod and the counter, which causes a problem relative to the improvement of the dimensional accuracy of the fixed dimension material to be fed.
In addition, in a conventional cutting apparatus which has a particularly large sized structure, a sub guide post is provided in addition to a main guide post for guiding the cutting head freely in the vertical direction. This sub guide post and the main vise device are provided in parallel, in the longitudinal direction. Accordingly, when the material feed vise device is closest to the main vice device, the sub guide post is between the main vice device and the material feed vise device, which gives rise to the problem that the remnant material length becomes large by the size of the sub guide.
In addition, with a cutting apparatus where the cutting head rotates horizontally for cutting diagonally to the longitudinal direction of the workpiece, the angle of rotation cannot be larger due to the existence of the sub guide post by its size.
Furthermore, in a large type of cutting apparatus, because the sub guide post is erected on the base on which is mounted the main vise device, this base must be large, and with a large base there is the problem that machining of the mounting seat for the sub guide post to be erected is difficult.
In addition, in conventional cutting apparatus where the sawblade as a cutting tool is tilted, the lower limiting position of the cutting head is always fixed. Accordingly, depending on the magnitude of the width of the cut workpiece, even after the cutting of the workpiece is completed, the cutting head continues to descend, and descends more than necessary, so that raising the efficiency of the operation is a problem.
In addition, in a cutting apparatus such as a horizontal bandsaw machine, a rotating brush is provided to brush off the chips which adhere to the bandsaw used as a cutting tool. Because this rotating brush is an expendable item, it must be replaced periodically. Accordingly, a threaded section is conventionally formed at the tip of the rotating shaft on which the rotating brush is mounted. Therefore, replacement of the rotating brush requires its removal from and remounting on the rotating shaft by the removal and installation of a nut on this threaded section. For this reason, a tool is required to rotate a conventional nut, and occasionally the tool or the nut is lost. In addition, there is also the problem that the removal and reinstallation of the rotating brush takes a comparatively long time.